I a very newbie, but I am not certain if this is the best place for my question. If not, please let me know where it should be.

I am learning about bitcoin mining and am interested in doing so by leasing access to mining equipment over the internet (at least to start).

I have looked at a few sites that facilitate such leasing. One in particular requires orders to be for a minimum hashrate of 50 TH/s.

I have also been looking at pools. I just looked at a few and they have total hashrates (a few minutes ago) ranging from 6 to 370 TH/s. When I look at recent earnings stats (20 days or so) it seems that the smaller ones tend to be the most profitable.

I don't understand how a newbie like me, placing a minimum order for such a small amount of money, could be such a large percentage of a pool's volume?

Also, is there an inherent reason why smaller pools are profitable? if so, would I destroy the profitability of a small pool by adding 50 TH/s to it?

Thank You
Jacob